Aircraft energy indicator generating system, device, and method

ABSTRACT

Present novel and non-trivial system, device, and method for generating an aircraft energy indicator(s) is disclosed. The energy indicator generating system is comprised of one or more sources of aircraft performance factors data, an image generator (IG), and a presentation system. The IG may be configured to receive the aircraft performance factors data representative of at least aircraft altitude and speed; determine descent path data as a function of at least the aircraft performance data; determine target aircraft energy data as a function of at least the descent path data; determine actual energy data as a function of at least the aircraft performance data; and generate presentation data as a function of the target energy data and the actual energy data, where the presentation data is representative of one or more images of an aircraft energy indicator presentable to a viewer.

BACKGROUND

Field of the Inventive Concepts

The inventive concepts disclosed herein pertain generally to the fieldof aircraft display units that present information to the pilot of anaircraft.

Description of the Related Art

A vertical descent path (VDP) of an aircraft's flight path is typicallyassigned a fixed vertical path angle (VPA). Perhaps the most common VPAis three degrees although this may differ due to, for instance, altitudeconstraints built into the VDP. When it comes time to fly the VDP, anaircraft system(s) may be configured (or programmed) to control theaircraft pitch so that the aircraft follows the VDP while maintaining adescent speed target through movement of the aircraft throttle(s). Anautothrottle system may increase the speed of the aircraft by “addingthrottle” (i.e., increasing engine thrust) and may decrease the speed byretarding the throttle without pilot intervention; however, the systemmay not decrease the throttle past a defined idle setting for theengines and, therefore may not reduce speed without pilot interventionof imparting “drag” through, for instance, the use of speed brakes if aspeed brake system is installed. If the actual VDP path on which theaircraft is flying is too steep and the drag is insufficient, the systemmay not be able to maintain the descent speed. When the VPA is a fixed,three degree angle, the amount of throttle required to maintain the VDPis typically above idle. The excess fuel consumption—the amount of fuelneeded to power the engines above idle—increases operating costs as fuelis wasted in light of the relatively large amount of total energyavailable to the aircraft during descent.

A flight idle descent (FID) path could be employed by utilizingpredictive atmospheric conditions, and the physical performance of theaircraft may be employed by an algorithm(s) to determine an idealdescent path that may never require the aircraft's throttles to moveabove idle and never require pilot intervention to impart additionaldrag. The aircraft's available total energy comprised of availablepotential energy and kinetic energy may be exploited along the FID pathsuch that the total energy expended equals the energy required tomaintain the desired descent speed of the FID path. Performance factorssuch as, for example, the drag of the aircraft, the predictedtemperatures and winds at points along the path, and weight of theaircraft may be used to create a FID path. The FID path may start from aTop of Descent (TOD) and end at approach start point (ASP) or a definedwaypoint such as, for example, a final approach fix of an instrumentapproach procedure. If the FID path requires a change of speed, this isachieved simply by changing the VPA without having to adjust thethrottles. Speed may be maintained through the descent by changing theVPA to manage the conversion of potential energy to kinetic energywithout the use of throttles.

The TOD is the point if flight where, if the engine thrust is reduced toidle and/or continues to operate at idle, the aircraft deceleratesthroughout the approach while reducing fuel consumption and reachingflap/slat retraction speeds and/or final approach speed. Unlike the FIDpath, the ASP could be defined by a specific geometric, fixed-angle paththat is not subjected to being altered, a determining factor in locatingits start point.

SUMMARY

The embodiments disclosed herein are directed to a system, device, andmethod for generating an energy indicator that is presentable to apilot. The indicator could be used in conjunction with the FID path toenhance situational awareness of a pilot by informing him or her whetherexcess energy will need to be bled off or a shortage of energy will needto be compensated by adding engine thrust.

In one aspect, embodiments of the inventive concepts disclosed hereinare directed to a system for generating aircraft energy indicator(s).The system may include a source of aircraft performance factor data, animage generator (IG), and a presentation system. In some embodiments,the presentation system may include a visual display unit, an auraladvisory unit, and/or a tactile advisory unit.

In another aspect, embodiments of the inventive concepts disclosedherein are directed to a device for generating aircraft energyindicator(s). The device may include the IG and may be configured (orprogrammed) to perform a method of generating energy indicator(s)presentable to a viewer.

In a further aspect, embodiments of the inventive concepts disclosedherein are directed to a method for generating aircraft energyindicator(s). When properly configured, the IG may acquire aircraftperformance factor data, determine descent path data as a function of atleast the aircraft performance factor, determine target aircraft energydata as a function of at least the descent path data, determine actualaircraft energy data as a function of at least the aircraft performancefactor data, and generate presentation data as a function of the firstenergy data and the second energy data. The target aircraft energy datacould include target aircraft potential energy, target aircraft kineticenergy, target aircraft total energy, or any combination of these. Theactual aircraft energy data could include actual aircraft potentialenergy, actual aircraft kinetic energy, actual aircraft total energy, orany combination of these.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a functional block diagram of an embodiment of a systemfor generating an energy indicator.

FIG. 2A presents an exemplary illustration of an energy indicatorpresented on a Head-Down Display unit.

FIG. 2B presents an exemplary illustration of an energy indicatorpresented on a Head-Up Display unit.

FIG. 3A presents a table containing results from a hypothetical flightidle descent algorithm.

FIG. 3B illustrates a hypothetical FID path.

FIG. 3C illustrates a graph and plots of target energies.

FIG. 4A presents a table containing total energy ratios at variousaltitudes and speeds.

FIG. 4B illustrates a graph plotting the data contained in the table ofFIG. 5A.

FIG. 4C illustrates energy indicators scaled to total energy ratios.

FIG. 5A illustrates maximum and minimum deviations of an energy indictorcorrelated to maximum altitude deviations.

FIG. 5B illustrates maximum and minimum deviations of an energy indictorcorrelated to maximum speed deviations.

FIG. 5C illustrates maximum and minimum deviations of an energy indictorcorrelated to maximum altitude deviations and maximum speed deviations.

FIG. 6A presents a table containing kinetic and potential energy ratiosat various altitudes and speeds.

FIG. 6B illustrates energy indicators scaled to kinetic and potentialenergy ratios.

FIG. 7A illustrates maximum and minimum deviations of an energy indictorcorrelated to maximum speed deviations.

FIG. 7B illustrates maximum and minimum deviations of an energy indictorcorrelated to maximum altitude deviations.

FIG. 8 illustrates a flowchart disclosing an embodiment of a method forgenerating an energy indicator.

DETAILED DESCRIPTION

In the following description, several specific details are presented toprovide a thorough understanding of embodiments of the inventiveconcepts disclosed herein. One skilled in the relevant art willrecognize, however, that the inventive concepts disclosed herein can bepracticed without one or more of the specific details, or in combinationwith other components. In other instances, well-known implementations oroperations are not shown or described in detail to avoid obscuringaspects of various embodiments of the inventive concepts disclosedherein.

FIG. 1 depicts a functional block diagram of an embodiment of an energyindicator generating system 100 suitable for implementation of thetechniques described herein. The functional blocks of the system 100include a navigation data source 110, a performance factors data source120, an image generator (IG) 130, and a presentation system 140.

The navigation data source 110 could include any source(s) whichprovides navigation data information in an aircraft. The navigation datasource 110 may include, but is not limited to, an air/data system, anattitude heading reference system, an inertial guidance system (orinertial reference system), and a global navigation satellite system (orsatellite navigation system), all of which are known to those skilled inthe art. The navigation data source 110 could provide navigation dataincluding, but not limited to, geographic position, altitude, heading,attitude, ground speed, air speed, and/or time. Aircraft position may becomprised of geographic position (e.g., latitude and longitudecoordinates) and altitude, and ground track may be derived from eithergeographic position, aircraft position, or both. Aircraft orientationmay be comprised of pitch, roll, and/or yaw information related to theattitude of the aircraft.

The navigation data source 110 could further include a flight managementsystem (FMS) which could perform a variety of functions to help the crewin the management of the flight. These functions could include receivinga flight plan (i.e., planned trajectory) and constructing a lateral andvertical flight plan (i.e., planned lateral and vertical trajectories)from the flight plan. The flight plan could be comprised of a series ofwaypoints, where each waypoint could include an altitude constraintassociated with it. A pilot could create a flight plan by enteringwaypoints stored in a database or select a flight plan stored in adatabase of the FMS. In some embodiments, the flight plan could bereceived and loaded into the FMS automatically through a data linksystem.

In the performance of its many functions, the FMS could compute avariety of distances and/or surface lengths. Further, distances and/orlengths could be computed by the pilot and entered into the FMS in someembodiments. The FMS may perform a variety of functions to help the crewin the management of the flight. In the performance of its manyfunctions, the FMS may receive navigation data from the navigation datasource 110 such as those discussed above.

It should be noted that, in some embodiments for any source or system inan aircraft including the navigation data source 110, data could becomprised of any analog or digital signal, either discrete orcontinuous, which could contain information or be indicative ofinformation. In some embodiments, aircraft could mean any vehicle whichis able to fly through the air or atmosphere including, but not limitedto, lighter than air vehicles and heavier than air vehicles, wherein thelatter may include manned or unmanned fixed-wing and rotary-wingvehicles.

The performance factors data source 120 could be comprised of any sourceor combination of sources—including the navigation data source 110—thatcould provide aircraft performance factors which may be employed todefine aircraft performance and determine a plurality of descent pathsand/or descent path profiles as discussed herein. For example, theperformance factors data source 120 could be comprised of one or moreaircraft systems or components thereof. The performance factors datasource 120 could include real-time system or sensor data, signal inputfrom a plurality of aircraft systems or sensors, and information fromany database or source. Detailed discussions of the aircraft performancefactors and the employment thereof have been disclosed (and discussed asinput factors) by Wichgers et al in U.S. Pat. No. 8,234,020 entitled“System and Methods for Generating Alert Signals in a Terrain AwarenessWarning System,” which is incorporated herein by reference in itsentirety. In some embodiments, the performance factors data source 120could be configured to provide aircraft performance factors data to theIG 130 for subsequent processing as discussed herein.

The IG 130 could include any electronic data processing unit whichexecutes software or computer instruction code that could be stored,permanently or temporarily, in a digital memory storage device or anon-transitory computer-readable media including, but not limited to,random access memory (RAM), read-only memory (ROM), compact disc (CD),hard disk drive, diskette, solid-state memory, Personal Computer MemoryCard International Association card (PCMCIA card), secure digital cards,and compact flash cards. The IG 130 may be driven by the execution ofsoftware or computer instruction code containing algorithms developedfor the specific functions embodied herein. The IG 130 may be anapplication-specific integrated circuit (ASIC) customized for theembodiments disclosed herein. Common examples of electronic dataprocessing units are microprocessors, Digital Signal Processors (DSPs),Programmable Logic Devices (PLDs), Programmable Gate Arrays (PGAs), andsignal generators; however, for the embodiments herein, the term“processor” is not limited to such processing units and its meaning isnot intended to be construed narrowly. For instance, the IG 130 couldalso consist of more than one electronic data processing unit. In someembodiments, the IG 130 could be a processor(s) used by or inconjunction with any other system of the aircraft including, but notlimited to, the navigation data source 110, the performance factors datasource 120, and the presentation system 140.

In some embodiments, the terms “programmed” and “configured” aresynonymous. The IG 130 may be electronically coupled to systems and/orsources to facilitate the receipt of input data. In some embodiments,operatively coupled may be considered as interchangeable withelectronically coupled. It is not necessary that a direct connection bemade; instead, such receipt of input data and the providing of outputdata could be provided through a data bus, through a wireless network,or as a signal received and/or transmitted by the IG 130 via a physicalor a virtual computer port. The IG 130 may be programmed or configuredto execute the method discussed in detail below. The IG 130 may beprogrammed or configured to provide output data to various systemsand/or units including, but not limited to, the presentation system 140.

The presentation system 140 could be comprised of any unit of whichvisual, aural, and/or tactile indications may be presented to the pilotincluding, but not limited to, a visual display unit(s) 142, an auraladvisory unit 144, and/or a tactile advisory unit 146. The visualdisplay unit 142 could be comprised of any unit of which information maybe presented visually to the pilot. The visual display unit 142 could bepart of an Electronic Flight Information System (EFIS) and could becomprised of, but is not limited to, a Primary Flight Display (PFD),Navigation Display (ND), Head-Up Display (HUD), Head-Down Display (HDD),Multi-Purpose Control Display Unit, Engine Indicating and Crew AlertingSystem, Electronic Centralized Aircraft Monitor, Multi-Function Display,Side Displays, Electronic Flight Bags, Portable Electronic Devices(e.g., laptops, smartphones, tablets, and/or user-wearable devices suchas head mounted devices).

The visual display unit 142 could be capable of projecting and/orpresenting a one or more energy indicators. Energy indicators may bepresented graphically and/or textually as disclosed below. Energyindicators may include alerts and/or non-alert(s). Alerts may be basedon level of threat or conditions requiring immediate crew awareness orattention. Caution alerts may be alerts requiring immediate crewawareness in which subsequent corrective action will normally benecessary. Warning alerts may be alerts requiring immediate crew action.In some embodiments, both caution and warning alerts may be presented incombination with or simultaneous to aural advisories and/or tactileadvisories. Non-alerts may be any other information not requiringimmediate crew attention or awareness. Alerts may be presented visuallyby depicting one or more colors and may be presented on a display unitindicating one or more levels of threat. For the purpose of illustrationand not limitation, amber or yellow may indicate a caution alert, redmay indicate a warning alert, and green or cyan may indicate anon-alert.

The aural advisory unit 144 may be any unit capable of producing auraladvisories. Aural advisories may be discrete sounds, tones, and/orverbal statements used to annunciate a condition, situation, or event.Examples of aural advisories are provided below. In some embodiments,both aural advisories could be presented in combination with orsimultaneous to visual alerts and/or tactile advisories.

The tactile advisory unit 146 may be any unit capable of producingtactile advisories. Tactile advisories may be any tactile stimulus topresent a condition, situation, or event to the pilot such as, but notlimited to, a warning alert and/or a caution alert. Examples of tactilestimuli include a “stick shaker” and a vibrating seat (e.g., a pilot'sseat outfitted with a vibrating device). Moreover, tactile advisoriescould be presented in combination with or simultaneous to visual alertsand/or aural advisories. In some embodiments, one or more units of thepresentation system 140 may receive presentation data provided by IG130.

The visual display unit 142 may be configured to present one or moredisplay(s) or image(s). In some embodiments, the terms “display” and“image” are interchangeable and treated synonymously.

Referring now to FIG. 2A, an exemplary depiction of a visual displayunit 142-A comprised of an HDD has been configured to present tacticalinformation to the pilot or flight crew against the background of athree-dimensional image of terrain and sky. FIG. 2B provides anexemplary depiction of a visual display unit 142-A comprised of a HUDunit for presenting tactical information to the pilot or flight crewagainst the background of a three-dimensional image of terrain and sky.Both the HDD unit and HUD unit could be employed as display unitsconfigured to present SVS image(s), EVS image(s), or combined SVS-EVSimage(s). It should be noted that the tactical information depicted onthe HDD unit and/or HUD unit has been made minimal for the sake ofpresentation and is not indicative of the plurality of indications orinformation with which it may be configured. Because the indications orinformation shown in FIGS. 2A and 2B are well-known to those skilled inthe art, a discussion of the specific tactical information shown on themis not provided herein.

In addition, energy indicators 150 and 160 that are disclosed herein arepresented on the visual display units 142 of FIGS. 2A and 2B,respectively. The location for presenting the energy indictor 150 isconfigurable by a manufacturer and/or end-user. In FIGS. 3A and 3B, theenergy indictors 150 and 160 have been located in between the airspeedindicator and either the attitude indicator or altitude indictor of animage presented on the visual display unit 142 that has been configuredfor presenting tactical information. In some embodiments, a manufacturerand/or end-user could configure the energy indicator for anotherlocation within the same image or within another image other than onepresenting tactical flight information. Also, although the orientationof the energy indicators 150 and 160 are vertically-disposed, theorientation is not limited to this disposition but includes otherorientations that may be preferable to the manufacturer and/or end-usersuch as, but not limited to, a horizontally-disposed energy indicator.

Some advantages and benefits of embodiments discussed herein are shownin FIGS. 3A through 7B by illustrating how a flight idle descent (FID)path may be used to generate more than one energy indictor and enhancesituational awareness by informing the pilot of whether there exists anexcess or deficiency of energy along the FID path. As discussed above,the FID path could be employed by utilizing predictive atmosphericconditions, and the physical performance of the aircraft may be employedby an FID algorithm(s) to determine an ideal descent path that may neverrequire the aircraft's throttles to move above idle and never requirethe intervention of a pilot to impart additional drag or engine thrust.

For the sole purpose of illustration, it will be assumed that ahypothetical FID algorithm has been applied for a hypothetical aircraft.Partial hypothetical results are shown in table of FIG. 3A under thecolumns of altitude, range, true airspeed (KTAS) in knots, weight, andvertical path angle (VPA). Known to those skilled in the art, energyalgorithms have been applied to the results of the FID algorithm toproduce a target kinetic energy (KE), target potential energy (PE), andtarget total energy (TE) corresponding to the FID path. KE has beendetermined as a function of at least square of speed, PE has beendetermined as a function of at least altitude, and TE has beendetermined as the sum of these two energies.

FIG. 3B illustrates a hypothetical FID path generated from datacontained in the table of FIG. 3A, where the range and altitude are notdrawn to scale. As observed, the speeds are not constant, and there is agradual deceleration from 466 KTAS beginning from the altitude of 30,000feet. Also, the VPA is not constant, a distinguishable characteristic ofdescent paths from which a constant angle is assumed.

FIG. 3C illustrates a graph in which the target KE, target PE, andtarget TE have been plotted. As expected from the data in the table,target KE as a function of speed, and target PE varies as a function ofaltitude.

Referring to FIGS. 4A and 4B, the effect that actual altitude and actualspeed have on PE, KE, and TE is illustrated. From the table of FIG. 3A,the target KTAS for the FID path at a range of 18.8 NM (nautical miles)at 40,000 feet is 459 knots. As shown in row A of FIG. 4A, the actualKTAS and the actual altitude at the range of 18.8 NM are the same as thetarget VTAS and target altitude for the range. The actual KE, actual PE,and actual TE at the range are 948 Mega Joules (MJ), 4,657 MJ and 5,604MJ, respectively, the same as the respective target KE, target PE, andtarget TE. The TE ratio (a ratio of actual TE to target TE) andcorresponding TE percentage are 1.000 and 0.0, respectively, as shown inrow A.

FIG. 4B illustrates a graph in which TE ratios and actual KTAS are shownwith the FID path. As observed, the TE ratio of 1.000 and the actualKTAS of 459 KTAS are shown at the actual altitude of 40,000 and range of18.8 NM.

As shown in row B of FIG. 4A, the actual KTAS at the range of 18.8 NM isthe same as the target VTAS of 459 knots for the range, but the actualaltitude is 42,500 feet, 2,500 feet above the target altitude. Thehigher altitude is also illustrated by comparing the actual PE of 4,395MJ with the target PE of 4,137 MJ, an excess of both PE and TE of 258 MJ(the KE is unchanged for this KTAS and range). The TE ratio andcorresponding TE percentage are 1.051 and 5.1, respectively, as shown inrow B. As shown in FIG. 4B, the TE ratio and the actual KTAS are shownat the actual altitude and range.

As shown in row C of FIG. 4A, the actual altitude of 40,000 feet at therange of 18.8 NM is the same as the target altitude of 40,000 feet forthe range, but the actual KTAS is 469 knots, 10 knots above the targetKTAS. The higher KTAS is also illustrated by comparing the actual KE of990 MJ with the target KE of 948 MJ, an excess of both KE and KE of 42MJ (the PE is unchanged for this altitude and range). The TE ratio andcorresponding TE percentage are 1.008 and 0.8, respectively, as shown inrow C. As shown in FIG. 4B, the TE ratio and the actual KTAS are shownat the actual altitude and range.

As shown in row D of FIG. 4A, the actual altitude at the range of 18.8NM is 37,500 feet, 2,500 feet below the target altitude for the range.Also, the actual KTAS at the range is 479 knots, 20 knots above thetarget KTAS. The lower altitude is illustrated by comparing the actualPE of 3,879 MJ with the target PE of 4,137 MJ, a deficiency of PE of 258MJ. The higher KTAS is illustrated by comparing the actual KE of 1032 MJwith the target KE of 948 MJ, an excess of KE of 84 MJ. The actual TE atthe range is 4,911 MJ, a deficiency of TE of 174 MJ when compared withthe target TE of 5,085 MJ. The TE ratio and corresponding TE percentageare 0.966 and −3.4, respectively, as shown in row D. As shown in FIG.4B, the TE ratio and the actual KTAS are shown at the actual altitudeand range.

As shown in rows E through M of the table of FIG. 4A, combinations ofactual altitudes and actual KTASs are shown for ranges of 44.3 NM, 70.9NM, and 99.2 NM. For each of these combinations, the values of the TEratios and corresponding TE percentages are shown. As observed in FIG.4B, these TE ratios and actual KTASs are shown with the FID path.

Referring to FIG. 4C, a plurality of energy indicators A through Mcorresponding to the rows of data in the table shown in FIG. 4A isillustrated. As observed in FIG. 4C, each indicator is comprised of areference position (indicated by 0), a minimum position (indicated by−10.0), and a maximum position (indicated by 10.0), where the reference,minimum, and maximum positions may be correlated to TE percentages of0.0, −10.0, and 10.0. In addition, the energy indicator could be furthercomprised of a variably-sized bar, the size of which varies with atarget TE deviation, that is, the deviation of an actual TE from atarget TE. As such, the excess or deficiency of TE correlating to theFID path may be graphically presented to the pilot; a relativelysmall-sized bar may indicate the need for a minimal amount of manualintervention, whereas a relatively large-sized bar may indicate the needfor an aggressive amount of manual intervention.

Energy indicator A of FIG. 4C is indicative of the target TE deviationfor TE shown row A of FIG. 4A; the TE percentage of row A is 0.0,corresponding to a target TE deviation of 0.0 as shown in energyindicator A. Energy indicator B is indicative of the target TE deviationfor TE shown in row B; the TE percentage of row B is 5.1, correspondingto a target TE deviation of 5.1 as shown by the size of the bar inenergy indicator B. Energy indicator C is indicative of the target TEdeviation for TE shown in row C; the TE percentage of row C is 0.8,corresponding to a target TE deviation of 0.8 shown by the size of thebar in energy indicator C. Energy indicator D is indicative of thetarget TE deviation for TE shown in row D; the TE percentage of row D is−3.4, corresponding to a target TE deviation of −3.4 shown by the sizeof the bar in energy indicator D. For the remaining energy indicators Ethrough M, each is indicative of the target TE deviation shown in rows Ethrough M, respectively; each TE deviation corresponding to one of theTE percentages of the rows is indicated by the size of the bar shown inits respective energy indicator of FIG. 4C. It should be noted that,although numerical indications have been included in the energyindicators A through M, some or all of them could be excluded from beingpresented.

Referring to energy indicators K and M of FIG. 4C, the TE percentages ofrows K and M exceed the indicator's maximum and minimum TE deviations,respectively. In these cases, the size of the bars have reached amaximum size. In such instances, a manufacture and/or end-user provideone or more alerts produced via the aural advisory unit 144 and/ortactile advisory unit 146. For example, the bar could be configured tochange color and/or flash, textual and/or aural indications could bepresented, and/or a stick shaker or seat vibrating device could beactivated to draw the pilot's attention to an unwanted or undesirablesituation in need of immediate intervention.

In some embodiments, the maximum and minimum deviations indicated by theenergy indictor could correlate to maximum altitude deviations from atarget altitude. From the preceding discussion, the target KTAS for thetarget altitude of 40,000 feet and range of 18.8 NM is 459 knots.Referring to FIG. 5A, the maximum deviation from the target altitude fora given range is assumed to equal 500 feet. For the target altitude of40,000 feet, the maximum deviations correspond to actual altitudes of40,500 and 39,500 feet. As shown in the left-hand table of FIG. 5A, theactual TE for each of these actual altitudes is 5,137 MJ and 5,033 MJ,respectively. From the actual TEs, the maximum position (indicated by+1.0) on the energy indicator could correlate to 5,137 MJ, the referenceposition (indicated by 0.0) to 5,085 MJ, and the minimum position(indicated by −1.0) to 5,033 MJ. For the target altitudes of 5,000 feetto 35,000 feet and incremented by 5,000 feet intervals, the maximumdeviations of altitudes of 500 feet above and below the target altitudeare shown in the left-hand table. From these TEs, correlated maximum,reference, and minimum positions for the energy indicator are providedin the upper table.

FIG. 5A provides two examples to illustrate how the height of the bar ofthe energy indicator may be determined, for example, throughinterpolation. In Example 1, it is assumed that the actual TE for theaircraft flying at an altitude of 20,000 feet is 2,800 MJ. From the toptable, the actual TE corresponding to the maximum deviation of thetarget altitude of 20,000 feet is 2,836 MJ, and the target TE is 2,785MJ. After interpolation, the height of the bar has been determined to be+0.29 as shown. Likewise, in Example 2, it is assumed that the actual TEfor the aircraft flying at an altitude of 30,000 feet is 4,035 MJ. Fromthe top table, the actual TE corresponding to the maximum deviation ofthe target altitude of 30,000 feet is 4,025 MJ, and the target TE is4,077 MJ. After interpolation, the height of the bar has been determinedto be −0.81 as shown.

In some embodiments, the maximum and minimum deviations indicated by theenergy indictor could correlate to maximum speed deviations from atarget KTAS. From the preceding discussion, the target altitude for thetarget KTAS of 459 knots and range of 18.8 NM is 40,000 feet. Referringto FIG. 5B, the maximum deviation from the target KTAS for a given rangeis assumed to equal 15 knots. For the target KTAS of 459 knots, themaximum deviations correspond to actual KTASs of 474 and 444 knots. Asshown in the left-hand table of FIG. 5B, the actual TE for each of theseactual KTASs is 5,148 MJ and 5,024 MJ, respectively. From the actualTEs, the maximum position on the energy indicator could correlate to5,148 MJ, the reference position to 5,085 MJ, and the minimum positionto 5,024 MJ. For the target KTASs corresponding to target altitudes of5,000 feet to 35,000 feet and incremented by 5,000 feet intervals, themaximum deviations of KTASs of 15 knots feet above and below the targetKTAS are shown in the left-hand table. From these TEs, correlatedmaximum, reference, and minimum positions for the energy indicator areprovided in the upper table.

Similar to the examples of FIG. 5A, two examples are provided in FIG. 5Bto illustrate how the height of the bar of the energy indicator may bedetermined, for example, through interpolation. In Example 1, it isagain assumed that the actual TE for the aircraft flying at an altitudeof 20,000 feet is 2,800 MJ. From the top table, the actual TEcorresponding to the maximum deviation of the target altitude of 20,000feet is 2,840 MJ, and the target TE is 2,785 MJ. After interpolation,the height of the bar has been determined to be +0.28 as shown. InExample 2, it is again assumed that the actual TE for the aircraftflying at an altitude of 30,000 feet is 4,035 MJ. From the top table,the actual TE corresponding to the maximum deviation of the targetaltitude of 30,000 feet is 4,015 MJ, and the target TE is 4,077 MJ.After interpolation, the height of the bar has been determined to be−0.67 as shown.

In some embodiments, the maximum and minimum deviations indicated by theenergy indictor could correlate to both maximum altitude deviations andmaximum speed deviations from a target altitude and KTAS, respectively.From the preceding discussion, the target altitude is 40,000 feet andfor the target KTAS of 459 knots for a range of 18.8 NM. Referring toFIG. 5C, the maximum deviation from the target altitude for a givenrange is assumed to equal 500 feet, and the maximum deviation from thetarget KTAS is assumed to equal 15 knots. For the target altitude of40,000 feet, the maximum deviations correspond to actual altitudes of40,500 and 39,500 feet; for the target KTAS of 459 knots, the maximumdeviations correspond to actual KTASs of 474 and 444 knots. As shown ina tables of FIG. 5C, the actual TE for each of the actual altitude of40,500 and actual KTAS of 444 is 5,199 MJ, and the actual TE for each ofthe actual altitude of 39,500 and actual KTAS of 474 is 4,972 MJ. Fromthese actual TEs, the maximum position on the energy indicator couldcorrelate to 5,199 MJ, the reference position to 5,085 MJ, and theminimum position to 4,972 MJ. For the target altitudes and target KTASscorresponding to target altitudes of 5,000 feet to 35,000 feet andincremented by 5,000 feet intervals, the maximum deviations of altitudesof 500 feet above and below the target altitude and KTASs of 15 knotsfeet above and below the target KTAS are shown in the left-hand table.From these TEs, correlated maximum, reference, and minimum positions forthe energy indicator are provided in the upper table.

Similar to the examples of FIGS. 5A and 5B, two examples are provided inFIG. 5C to illustrate how the height of the bar of the energy indicatormay be determined, for example, through interpolation. In Example 1, itis again assumed that the actual TE for the aircraft flying at analtitude of 20,000 feet is 2,800 MJ. From the top table, the actual TEcorresponding to the maximum deviation of the target altitude of 20,000feet is 2,891 MJ, and the target TE is 2,785 MJ. After interpolation,the height of the bar has been determined to be +0.14 as shown. InExample 2, it is again assumed that the actual TE for the aircraftflying at an altitude of 30,000 feet is 4,035 MJ. From the top table,the actual TE corresponding to the maximum deviation of the targetaltitude of 30,000 feet is 3,963 MJ, and the target TE is 4,077 MJ.After interpolation, the height of the bar has been determined to be−0.37 as shown.

As discussed above, the target KTAS for the FID path at a range of 18.8NM (nautical miles) at 40,000 feet is 459 knots. Referring to FIG. 6A,the actual KTAS and the actual altitude at the range of 18.8 NM shown inrow N are the same as the target VTAS and target altitude for the range.The actual KE, actual PE, and actual TE at the range are 948 MJ, 4,657MJ and 5,604 MJ, respectively, the same as the respective target KE,target PE, and target TE. The KE ratio (a ratio of actual KE to targetKE) and corresponding KE percentage are 1.000 and 0.0 percent,respectively, as shown in row N. In addition, the PE ratio (a ratio ofactual PE to target PE) and corresponding PE percentage are 1.000 and0.0, respectively, as also shown in row N.

As shown in row O of FIG. 6A, the actual KTAS at the range of 18.8 NM isthe same as the target VTAS of 459 knots for the range, but the actualaltitude is 42,500 feet, 2,500 feet above the target altitude. Thehigher altitude is also illustrated by comparing the actual PE of 4,395MJ with the target PE of 4,137 MJ, an excess of both PE and TE of 258 MJ(the KE is unchanged for this KTAS and range). The PE ratio andcorresponding PE percentage are 1.062 and 6.2, respectively, as shown inrow O.

As shown in row P of FIG. 6A, the actual altitude of 40,000 feet at therange of 18.8 NM is the same as the target altitude of 40,000 feet forthe range, but the actual KTAS is 469 knots, 10 knots above the targetKTAS. The higher KTAS is also illustrated by comparing the actual KE of990 MJ with the target KE of 948 MJ, an excess of both KE and KE of 42MJ (the PE is unchanged for this altitude and range). The KE ratio andcorresponding KE percentage are 1.044 and 4.4, respectively, as shown inrow P.

As shown in row Q of FIG. 6A, the actual altitude at the range of 18.8NM is 37,500 feet, 2,500 feet below the target altitude for the range.Also, the actual KTAS at the range is 479 knots, 20 knots above thetarget KTAS. The lower altitude is illustrated by comparing the actualPE of 3,879 MJ with the target PE of 4,137 MJ, a deficiency of PE of 258MJ. The higher KTAS is illustrated by comparing the actual KE of 1032 MJwith the target KE of 948 MJ, an excess of KE of 84 MJ. The PE ratio andcorresponding PE percentage are 0.937 and −6.3, respectively, as shownin row Q. The KE ratio and corresponding KE percentage are 1.089 and8.9, respectively, as also shown in row Q.

As shown in rows R through Z of the table of FIG. 6A, combinations ofactual altitudes and actual KTASs are shown for ranges of 44.3 NM, 70.9NM, and 99.2 NM. For each of these combinations, the values of the PEratios and corresponding PE percentages as well as the values of the KEratios and corresponding KE percentages are shown.

Referring to FIG. 6B, a plurality of energy indicators N through Zcorresponding to the rows of data in the table shown in FIG. 6A isillustrated. As observed in FIG. 6B, each N though Z indicator may becomprised of separate KE and PE indicators, each being comprised of areference position (indicated by 0), a minimum position (indicated by−10.0), and a maximum position (indicated by 10.0); the reference,minimum, and maximum positions for both the KE and PE indicators may becorrelated to KE and PE percentages of 0.0, −10.0, and 10.0,respectively. In addition, each KE and PE energy indicator could befurther comprised of a variably-sized bar, the size of which varies witha target KE and PE deviation. As such, the excess or deficiency of KEand PE correlating to the FID path may be graphically presented to thepilot.

The KE energy indicator N of FIG. 6B is indicative of the target KEdeviation for KE shown row N of FIG. 6A; the KE percentage of row N is0.0, corresponding to a target KE deviation of 0.0 as shown in KE energyindicator N. The PE energy indicator N of FIG. 6B is indicative of thetarget PE deviation for PE shown row N of FIG. 6A; the PE percentage ofrow N is 0.0, corresponding to a target PE deviation of 0.0 as shown inPE energy indicator N.

The KE energy indicator O is indicative of the target KE deviation forKE shown in row P; the KE percentage of row O is 0.0, corresponding to atarget KE deviation of 0.0 as shown by the size of the bar in KE energyindicator O. The PE energy indicator O of FIG. 6B is indicative of thetarget PE deviation for PE shown row O of FIG. 6A; the PE percentage ofrow O is 6.2, corresponding to a target PE deviation of 6.2 as shown inPE energy indicator O.

The KE energy indicator P is indicative of the target KE deviation forKE shown in row P; the KE percentage of row P is 4.4, corresponding to atarget KE deviation of 4.4 as shown by the size of the bar in KE energyindicator P. The PE energy indicator P of FIG. 6B is indicative of thetarget PE deviation for PE shown row P of FIG. 6A; the PE percentage ofrow P is 0.0, corresponding to a target PE deviation of 0.0 as shown inPE energy indicator N.

The KE energy indicator Q is indicative of the target KE deviation forKE shown in row Q; the KE percentage of row Q is 8.9, corresponding to atarget KE deviation of 8.9 as shown by the size of the bar in KE energyindicator Q. The PE energy indicator Q of FIG. 6B is indicative of thetarget PE deviation for PE shown row Q of FIG. 6A; the PE percentage ofrow Q is −6.3, corresponding to a target PE deviation of −6.3 as shownin PE energy indicator Q.

For the remaining KE and PE energy indicators R through Z, each isindicative of the target KE and PE deviations shown in rows R through Z,respectively; each KE and PE deviation corresponding to one of the KEand PE percentages of the rows is indicated by the size of the bar shownin its respective KE and PE energy indicator of FIG. 6B. It should benoted that, although numerical indications have been included in theenergy indicators N through Z, some or all of them could be excludedfrom being presented.

As stated above, the maximum and minimum deviations indicated by theenergy indictor could correlate to maximum speed deviations from atarget KTAS in some embodiments. From the preceding discussion, thetarget altitude for the target KTAS of 459 knots and range of 18.8 NM is40,000 feet. Referring to FIG. 7A, the maximum deviation from the targetKTAS for a given range is assumed to equal 15 knots. For the target KTASof 459 knots, the maximum deviations correspond to actual KTASs of 474and 444 knots. As shown in the left-hand table of FIG. 7A, the actual KEfor each of these actual KTASs is 1,011 MJ and 887 MJ, respectively.From the actual KEs, the maximum position on the KE energy indicatorshown in FIG. 7B and indicated by +1.0 could correlate to 1,011 MJ, thereference position (indicated by 0.0) to 948 MJ, and the minimumposition (indicated by −1.0) to 887 MJ. For the target KTASscorresponding to target altitudes of 5,000 feet to 35,000 feet andincremented by 5,000 feet intervals, the maximum deviations of KTASs of15 knots feet above and below the target KTAS are shown in the left-handtable. From these KEs, correlated maximum, reference, and minimumpositions for the KE energy indicator are provided in the right-handtable.

As stated above, the maximum and minimum deviations indicated by theenergy indictor could correlate to maximum altitude deviations from atarget altitude in some embodiments. From the preceding discussion, thetarget KTAS for the target altitude of 40,000 feet and range of 18.8 NMis 459 knots. Referring to FIG. 7B, the maximum deviation from thetarget altitude for a given range is assumed to equal 500 feet. For thetarget altitude of 40,000 feet, the maximum deviations correspond toactual altitudes of 40,500 and 39,500 feet. As shown in the left-handtable of FIG. 7B, the actual PE for each of these actual altitudes is4,189 MJ and 4,085 MJ, respectively. From the actual PEs of FIG. 7B, themaximum position on the PE energy indicator (indicated by +1.0) couldcorrelate to 4,189 MJ, the reference position (indicated by 0.0) to4,137 MJ, and the minimum position (indicated by −1.0) to 4,085 MJ. Forthe target altitudes of 5,000 feet to 35,000 feet and incremented by5,000 feet intervals, the maximum deviations of altitudes of 500 feetabove and below the target altitude are shown in the left-hand table.From these PEs, correlated maximum, reference, and minimum positions forthe PE energy indicator are provided in the upper table.

FIG. 7B provides two examples to illustrate how the height of the bar ofboth the KE and PE energy indicators may be determined, for example,through interpolation. In Example 1, it is assumed that the actual KEfor the aircraft flying at an altitude of 20,000 feet is 700 MJ and theactual PE is 2,100 MJ. From the right-hand table of FIG. 7A, the actualKE corresponding to the maximum deviation of the target altitude of20,000 feet is 666 MJ, and the target KE is 719 MJ; after interpolation,the height of the bar for the KE energy indicator has been determined tobe −0.36 as shown. From the upper table of FIG. 7B, the actual PEcorresponding to the maximum deviation of the target altitude of 20,000feet is 2,117 MJ, and the target KE is 2,066 MJ; after interpolation,the height of the bar for the PE energy indicator has been determined tobe +0.67 as shown.

Likewise, in Example 2, it is assumed that the actual KE for theaircraft flying at an altitude of 30,000 feet is 960 MJ and the actualPE is 3,075 MJ. From the right-hand table of FIG. 7A, the actual KEcorresponding to the maximum deviation of the target altitude of 30,000feet is 914 MJ, and the target KE is 976 MJ; after interpolation, theheight of the bar for the KE energy indicator has been determined to be−0.26 as shown. From the upper table of FIG. 7B, the actual PEcorresponding to the maximum deviation of the target altitude of 30,000feet is 3,049 MJ, and the target KE is 3,101 MJ; after interpolation,the height of the bar for the PE energy indicator has been determined tobe −0.49 as shown.

Similar to the examples of FIG. 5A, two examples are provided in FIG. 5Bto illustrate how the height of the bar of the energy indicator may bedetermined, for example, through interpolation. In Example 1, it isagain assumed that the actual TE for the aircraft flying at an altitudeof 20,000 feet is 2,800 MJ. From the top table, the actual TEcorresponding to the maximum deviation of the target altitude of 20,000feet is 2,840 MJ, and the target TE is 2,785 MJ. After interpolation,the height of the bar has been determined to be +0.28 as shown. InExample 2, it is again assumed that the actual TE for the aircraftflying at an altitude of 30,000 feet is 4,035 MJ. From the top table,the actual TE corresponding to the maximum deviation of the targetaltitude of 30,000 feet is 4,015 MJ, and the target TE is 4,077 MJ.After interpolation, the height of the bar has been determined to be−0.67 as shown.

In some embodiments, the maximum and minimum deviations indicated by theenergy indictor could correlate to both maximum altitude deviations andmaximum speed deviations from a target altitude and KTAS, respectively.From the preceding discussion, the target altitude is 40,000 feet andfor the target KTAS of 459 knots for a range of 18.8 NM. Referring toFIG. 5C, the maximum deviation from the target altitude for a givenrange is assumed to equal 500 feet, and the maximum deviation from thetarget KTAS is assumed to equal 15 knots. For the target altitude of40,000 feet, the maximum deviations correspond to actual altitudes of40,500 and 39,500 feet; for the target KTAS of 459 knots, the maximumdeviations correspond to actual KTASs of 474 and 444 knots. As shown ina tables of FIG. 5C, the actual TE for each of the actual altitude of40,500 and actual KTAS of 444 is 5,199 MJ, and the actual TE for each ofthe actual altitude of 39,500 and actual KTAS of 474 is 4,972 MJ. Fromthese actual TEs, the maximum position on the energy indicator couldcorrelate to 5,199 MJ, the reference position to 5,085 MJ, and theminimum position to 4,972 MJ. For the target altitudes and target KTASscorresponding to target altitudes of 5,000 feet to 35,000 feet andincremented by 5,000 feet intervals, the maximum deviations of altitudesof 500 feet above and below the target altitude and KTASs of 15 knotsfeet above and below the target KTAS are shown in the left-hand table.From these TEs, correlated maximum, reference, and minimum positions forthe energy indicator are provided in the upper table.

Similar to the examples of FIGS. 5A and 5B, two examples are provided inFIG. 5C to illustrate how the height of the bar of the energy indicatormay be determined, for example, through interpolation. In Example 1, itis again assumed that the actual TE for the aircraft flying at analtitude of 20,000 feet is 2,800 MJ. From the top table, the actual TEcorresponding to the maximum deviation of the target altitude of 20,000feet is 2,891 MJ, and the target TE is 2,785 MJ. After interpolation,the height of the bar has been determined to be +0.14 as shown. InExample 2, it is again assumed that the actual TE for the aircraftflying at an altitude of 30,000 feet is 4,035 MJ. From the top table,the actual TE corresponding to the maximum deviation of the targetaltitude of 30,000 feet is 3,963 MJ, and the target TE is 4,077 MJ.After interpolation, the height of the bar has been determined to be−0.37 as shown.

FIG. 8 depicts flowchart 200 disclosing an example of a method forgenerating one or more energy indicators, where the IG 130 may beprogrammed or configured with instructions corresponding to the modulesembodied in flowchart 200. In some embodiments, the IG 130 may be aprocessor or a combination of processors found in the presentationsystem 140 or any other system suitable for performing the task. Also,the IG 130 may be a processor of a module such as, but not limited to, aprinted circuit card having one or more input interfaces to facilitatethe two-way data communications of the IG 130, i.e., the receiving andproviding of data. As necessary for the accomplishment of the followingmodules embodied in flowchart 200, the acquiring of data is synonymousand/or interchangeable with the receiving and/or retrieving of data, andthe providing of data is synonymous and/or interchangeable with themaking available or supplying of data.

The method of flowchart 200 begins with module 202 with the IG 130acquiring of aircraft performance data representative of at leastmeasurements of speed and altitude from the aircraft performance factordata source 120. In some embodiments, the navigation data source 110 maybe included aircraft performance factor data source 120.

The flowchart 200 continues with module 204 with the IG 130 determiningdescent path data as a function of at least the aircraft performancedata, where the descent path data may be representative of a descentpath. In some embodiments, the descent path could be a FID path.

The flowchart 200 continues with module 206 with the IG 130 determiningof first aircraft energy data as a function of at least the descent pathdata, where the first aircraft energy data may be representative of ameasurement of reference aircraft energy. In some embodiments, thereference aircraft energy could be reference aircraft potential energythat could be a target potential energy. In some embodiments, thereference aircraft energy could be reference aircraft kinetic energythat could be a target kinetic energy. In some embodiments, thereference aircraft energy could be reference aircraft total energy thatcould be a target total energy. In some embodiments, the referenceaircraft energy could be any combination of the preceding referenceaircraft energies.

The flowchart 200 continues with module 208 with the IG 130 determiningof second aircraft energy data as a function of at least the aircraftperformance data, where the second aircraft energy data may berepresentative of a measurement of actual aircraft energy. In someembodiments, the actual aircraft energy could be actual aircraftpotential energy. In some embodiments, the actual aircraft energy couldbe actual aircraft kinetic energy. In some embodiments, the actualaircraft energy could be actual aircraft total energy. In someembodiments, the actual aircraft energy could be any combination of thepreceding actual aircraft energies.

The flowchart 200 continues with module 210 with the IG 130 generatingof presentation data as a function of the first energy data and thesecond energy data. The presentation data may be representative of oneor more images of aircraft energy indicators presentable to a viewer. Insome embodiments, each image could indicate a deviation of actualaircraft energy from reference aircraft energy. In some embodiments,each presentation data could be further representative of an auraladvisory and/or a tactile advisory. Then, the method of flowchart 200ends.

It should be noted that the method steps described above may be embodiedin computer-readable media stored in a non-transitory computer-readablemedium as computer instruction code. It shall be appreciated to thoseskilled in the art that not all method steps described must beperformed, nor must they be performed in the order stated.

As used herein, the term “embodiment” means an embodiment that serves toillustrate by way of example but not limitation.

It will be appreciated to those skilled in the art that the precedingexamples and embodiments are exemplary and not limiting to the scope ofthe inventive concepts disclosed herein. It is intended that allmodifications, permutations, enhancements, equivalents, and improvementsthereto that are apparent to those skilled in the art upon a reading ofthe specification and a study of the drawings are included within thetrue spirit and scope of the inventive concepts disclosed herein. It istherefore intended that the following appended claims include all suchmodifications, permutations, enhancements, equivalents, and improvementsfalling within the true spirit and scope of the inventive conceptsdisclosed herein.

What is claimed is:
 1. A system for generating an aircraft energyindicator, comprising: at least one source of aircraft performance data;and an image generator configured to: acquire first aircraft performancedata representative of at least first measurements of speed andaltitude; determine descent path data representative of a descent pathas a function of at least the first aircraft performance data; determinereference aircraft energy data as a function of at least the descentpath data; acquire second aircraft performance data representative of asecond measurement of speed and altitude subsequent to the firstaircraft performance data being acquired; determine actual aircraftenergy data as a function of at least the second aircraft performancedata; and generate presentation data as a function of the referenceaircraft energy data and the actual aircraft energy data, where thepresentation data is representative of at least one image of a scaled,aircraft energy indicator comprised of a reference position and agraphical indication and presentable to a pilot when provided to avisual display unit, such that a deviation of the graphical indicationfrom the reference position indicates a deviation of actual aircraftenergy from reference aircraft energy, where the deviation of thegraphical indication from the reference position enhances a pilot'ssituational awareness by indicating either an excess or a shortage ofaircraft energy.
 2. The system of claim 1, wherein the first aircraftperformance data and the second aircraft performance data are eachfurther representative of a measurement of weight.
 3. The system ofclaim 1, wherein the descent path is a flight idle descent path fromwhich a correlation exists between a plurality of altitudes and aplurality of reference speeds, where one altitude is correlated to onereference speed.
 4. The system of claim 1, wherein the referenceaircraft energy data is representative of at least one measurement ofreference aircraft potential energy, reference aircraft kinetic energy,and reference aircraft total energy.
 5. The system of claim 1, whereinthe actual aircraft energy data is representative of at least onemeasurement of actual aircraft potential energy, actual aircraft kineticenergy, and actual aircraft total energy.
 6. The system of claim 1,wherein the graphical indication is provided by a variably-sized bar,the size of which is dependent upon the deviation of actual aircraftenergy from reference aircraft energy.
 7. The system of claim 1, whereinthe presentation data is further representative of at least one of anaural advisory and a tactile advisory presentable via an aural advisoryunit and a tactile advisory unit, respectively.
 8. A device forgenerating an aircraft energy indicator, comprising: an image generatorconfigured to: acquire first aircraft performance data representative ofat least first measurements of speed and altitude; determine descentpath data representative of a descent path as a function of at least thefirst aircraft performance data; determine reference aircraft energydata as a function of at least the descent path data; acquire secondaircraft performance data representative of a second measurement ofspeed and altitude subsequent to the first aircraft performance databeing acquired; determine actual aircraft energy data as a function ofat least the second aircraft performance data; and generate presentationdata as a function of the reference aircraft energy data and the actualaircraft energy data, where the presentation data is representative ofat least one image of a scaled, aircraft energy indicator comprised of areference position and a graphical indication and presentable to a pilotwhen provided to a visual display unit, such that a deviation of thegraphical indication from the reference position indicates a deviationof actual aircraft energy from reference aircraft energy, where thedeviation of the graphical indication from the reference positionenhances a pilot's situational awareness by indicating either an excessor a shortage of aircraft energy.
 9. The device of claim 8, wherein thefirst aircraft performance data and the second aircraft performance dataare each further representative of a measurement of weight.
 10. Thedevice of claim 8, wherein the descent path is a flight idle descentpath from which a correlation exists between a plurality of altitudesand a plurality of reference speeds, where one altitude is correlated toone reference speed.
 11. The device of claim 8, wherein the referenceaircraft energy data is representative of at least one measurement ofreference aircraft potential energy, reference aircraft kinetic energy,and reference aircraft total energy.
 12. The device of claim 8, whereinthe actual aircraft energy data is representative of at least onemeasurement of actual aircraft potential energy, actual aircraft kineticenergy, and actual aircraft total energy.
 13. The device of claim 8,wherein the graphical indication is provided by a variably-sized bar,the size of which is dependent upon the deviation of actual aircraftenergy from reference aircraft energy.
 14. The device of claim 8,wherein the presentation data is further representative of at least oneof an aural advisory and a tactile advisory presentable via an auraladvisory unit and a tactile advisory unit, respectively.
 15. A methodfor generating an aircraft energy indicator, comprising: acquiring firstaircraft performance data representative of at least first measurementsof speed and altitude; determining descent path data representative of adescent path as a function of at least the first aircraft performancedata; determining reference aircraft energy data as a function of atleast the descent path data; acquiring second aircraft performance datarepresentative of a second measurement of speed and altitude subsequentto the first aircraft performance data being acquired; determine actualaircraft energy data as a function of at least the second aircraftperformance data; and generating presentation data as a function of thereference aircraft energy data and the actual aircraft energy data,where the presentation data is representative of at least one image of ascaled, aircraft energy indicator comprised of a reference position anda graphical indication and presentable to a pilot when provided to avisual display unit, such that a deviation of the graphical indicationfrom the reference position indicates a deviation of actual aircraftenergy from reference aircraft energy, where the deviation of thegraphical indication from the reference position enhances a pilot'ssituational awareness by indicating either an excess or a shortage ofaircraft energy.
 16. The method of claim 15, wherein the first aircraftperformance data and the second aircraft performance data are eachfurther representative of a measurement of weight.
 17. The method ofclaim 15, wherein the descent path is a flight idle descent path fromwhich a correlation exists between a plurality of altitudes and aplurality of reference speeds, where one altitude is correlated to onereference speed.
 18. The method of claim 15, wherein the referenceaircraft energy data is representative of at least one measurement ofreference aircraft potential energy, reference aircraft kinetic energy,and reference aircraft total energy.
 19. The method of claim 15, whereinthe actual aircraft energy data is representative of at least onemeasurement of actual aircraft potential energy, actual aircraft kineticenergy, and actual aircraft total energy.
 20. The method of claim 15,wherein the graphical indication is provided by a variably-sized bar,the size of which is dependent upon the deviation of actual aircraftenergy from reference aircraft energy.